Railroads have large rail yard centres or humps for arranging rail cars into lines which are linked with one or more engines. At the rail yard humps, individual rail cars or groups of rail cars are disengaged from their current line or engine and are then engaged with new lines and engines. In order to effect the engagement and disengagement of the rail cars, they must be slowed down or retarded substantially from their travel speed in order to ensure safe operation of the yard and to minimize damage in the engaging and disengaging process.
Devices called retarders are used to slow rail cars down in rail yards and normally have devices which engage at the outer and inner face of the wheel rims acting as a break on the wheels to frictionally squeeze the wheels as the cars pass through the retarder. In practice, the rail cars may be slowed from 18 miles an hour to 3 miles per hour as they pass through a typical retarder.
In order for the retarders to work effectively, there must be a minimum amount of friction between the retarder and the rail car wheels in order to function properly. Unfortunately, substances including oils, greases and commodities such as sugar, flour and syrup tend to accumulate on the wheels of rail cars, which tend to reduce the friction between the wheels and the retarder and reduce the effectiveness of the retarder. Grease and dirt on one wheel may carry over on to the retarder mechanisms and thereby contaminate the entire retarder mechanism rendering it inefficient or ineffective. This can result in a dangerous situation where the rail cars are moving far too quickly as they exit the retarder, resulting in damage to rail cars and unsafe operations. Therefore, there is a need to keep the rail wheels as clean as possible, particularly in rail yard humps where they are manipulated. There have been a number of different rail car wheels cleaning systems proposed and used in the past with varying amounts of effectiveness. One such rail car wheel cleaning system is described in U.S. Pat. No. 1,831,802 to Herbert L. Bone titled WHEEL SCRAPING APPARATUS and the like which was issued on Nov. 17, 1931. Another system is described in U.S. Pat. No. 5,991,952 titled RAIL CAR WHEEL CLEANING SYSTEM by inventor Robert R. Bintzler which was issued on Nov. 30, 1999.
All of these wheel car cleaning systems have varying degrees of effectiveness however one major drawback with all of these systems is the very high maintenance cost associated with keeping the cleaning systems effective and the significant amount of time required for adjusting and maintaining the systems to allow them to operate at optimal levels.
There is need for a rail car cleaning system which is simple, requires a minimal amount of maintenance, can be adjusted rapidly without great amounts of labour and manpower requirement, and provides consistent cleaning under a wide variety of operating and weather conditions.